1. Field of the Invention
The present invention relates to a method and an apparatus for the installation and removal of a piston rod from a cylinder bore of an internal combustion engine.
2. Discussion of the Related Art
A majority of internal combustion engines require internal servicing for repair at some point in their useful lives. In addition, servicing and replacement of worn internal engine parts can greatly extend an otherwise worn out engine's life. Internal servicing and parts replacement may, and typically will, require removing the piston and piston rods from the engine. This internal servicing may be required as part of a repair or replacement of the pistons, the piston rods themselves, the crank bearings, or some other engine parts and equipment. Separating a piston rod from an engine's cranking means and removing it through its associated cylinder bore or installing a piston rod through a cylinder bore and connecting it to the engine's cranking means is a typical internal servicing operation performed by the professional as well as the backyard mechanic.
When performing an installation or removal of a piston rod from an internal combustion engine, a major concern is metal to metal contact. Typically, the base or the bolts on the piston rod will fall against, and slide along, the bearing surface of the engines cranking means and against the cylinder bore wall. This metal to metal scraping can scar and damage the cylinder bore wall, the bearing surfaces on the engine's cranking means and the piston rod bolts. Further, the scraping can leave metal shavings in the engine's interior which can cause wear and damage during operation. There is also the chance that the piston rod will become caught inside the cylinder bore, requiring hammering on the piston head, which can lead to a cracked cylinder bore or broken piston.
The most common technique for removing a piston rod from an engine is accomplished by a mechanic or one with mechanical and automotive skills. The engine is first separated or removed from the automobile, boat or other vehicle which it powered. The engine is disassembled to expose the cranking means or more specifically, the connection of the piston rods to the cranking means or crankshaft. The piston rod is then disconnected from the engine's crankshaft by removing the fasteners, typically rod nuts, from the rod bolts, removing the lower seat of the piston rod and leaving the rod bolts exposed. The mechanic can now remove the piston and attached piston rod from the crankshaft and engine by pushing it out of its associated cylinder bore. As the piston rod is slid off of the engine's crankshaft, the piston rod bolts can scrape against the crankshaft, scarring the bearing surfaces, damaging the rod bolt threads and leaving metal shavings inside the engine block. As the piston rod is slid further out of the engine through the cylinder bore, the piston rod base and bolts can fall against and scrape the cylinder bore wall. This scraping can damage the finished piston ring and cylinder bore wall contact surface, the piston rod bolts, and also leave metal filing inside the engine. Thus, a second person is often required during removal of piston rods to support the piston rod and prevent its contact with other parts of the engine.
To replace the piston and attached piston rod, the sequence is reversed. The piston rod is placed, rod bolts first, into the cylinder bore and then pushed into the cylinder bore until the rod bolts contact the engine's cranking means or crankshaft. The rod bolts are then directed to straddle the engine's crankshaft until the base of the piston rod seats against the crankshaft. A second person is often required to ensure that the piston rod does not scrap or contact the cylinder bore as it is being inserted and pushed into the cylinder bore. Also, the second person can direct the piston rod bolts to straddle the crankshaft and prevent any contact with and scraping of the crankshaft.
Thus, a need exists for an apparatus that can be utilized to prevent metal to metal contact when removing or installing a piston rod into a cylinder bore and onto a crankshaft of an internal combustion engine. A need also exist for an apparatus and method that eliminates the need of an assistant when installing or removing piston rods from an engine. A need further exists for an apparatus and method that can be utilized on the majority of available internal combustion engines.